Question

$100c{m}^3$ of $N{H}_3$ diffuses through a pin hole in $32.5second$. How much time will $60cc$ of $N_2$ take to diffuse under the same conditions?

Answer 1

Using diffusion formula,

$\frac{r_{N{H}_3}}{r_{N_2}}=\sqrt{\frac{M_{N_2}}{M_{N{H}_2}}}$
$\frac{100/32.5}{60/t}=\sqrt{\frac{28}{17}}$
$\frac{100\times t}{60\times 32.5}=\sqrt{\frac{28}{17}}$
$t=25second$.